Door locks having remotely operated strikes are often used in security installations such as blocks of home units, hospitals, banks, commercial building and private dwellings. The doors are fitted with a retractable spring loaded latch bolt which upon closing rides over the edge of a strike plate and into a recess in said plate. The strike itself however is remotely operable between a locked mode in which the bolt is held within the plate recess and an unlocked mode in which the bolt is able to be pulled from the recess without retracting it. This arrangement allows the door to be self closing while at the same time it is still able to be locked or unlocked by remote activation of the strike.
An example of a conventional strike plate is shown in cross section by FIG. 1. The strike 1 is pivotal around a pin 2 between a locking position 3 and an unlocked position 4 so that the bolt 5 can be either held within recess 6 or released in the direction of arrow 8 to open the door. The actual movement of the strike is obtained through a system of levers and solenoid (not shown). There are however a number of disadvantages with these existing systems. For example a degree of sliding friction between the inside surface 7 of the strike and bolt must be overcome when releasing the lock and this can inhibit its operation. A relatively bulky (and in some instances easily accessible via joints) lever system is also required to withdraw and/or retain the security of the strike which retains the latch bolt tongue. This makes the mechanism easier to pick. The offset location of the pivot to one side of the recess also increases its size. Further, the existing lever system must be specially constructed for either fail safe or fail secure operation of the door lock and cannot be readily changed by the user.